This invention relates generally to a means for testing electrical systems and, more particularly, to a portable device for testing multiple sensing systems about aircraft.
Large commercial and military aircraft are equipped with numerous sensing systems which constantly monitor the condition of the aircraft. Besides the normal avionics by which the pilot flys the aircraft, other hydraulic and electrical systems must be monitored for safety and passenger comfort.
One such aircraft, the Air Force C-5A, which is currently the world's largest aircraft utilizes a system referred to as a Master Caution controller. This system is supplemented by a system known as the Auto Caution controller. The controllers are located on the aircraft flight deck and receive as input signals from the various sensing units located throughout the aircraft. The controller's output is sent to display panels located on the instrument panel before the pilot and co-pilot. The Master Caution controller display consists of 45 individual lights which flash to attract attention in the event of a system malfunction. The Auto Caution controller and display is similar and contains 15 individual lights. The pilot or co-pilot as a matter of procedure will press a reset switch which is internally lighted as each malfunction occurs. Pressing the switch stops the flashing light on the display panel and simultaneously shuts off the internally lighted reset switch. The malfunction is verified and the pilot will take corrective action.
In the particular system described and similar systems, it is very likely malfunctions will occur in the caution controller systems. One of the major areas of difficulty is in the display units for both the Master Caution controller and the Auto Caution controller systems. Frequently, short circuits occur in the display units which inevitably cause the controller unit to burn out and be rendered useless.
Currently, there is no means of simply, quickly and safely trouble shooting the controller system. The present procedure is to attempt to locate the defect and then replace the controller unit. In the event the short circuit is not found or there is more than a single defect, the replacement controller unit would immediately be burned out and have to be discarded. The circuitry will then have to be thoroughly and arduously inspected. Besides being time consuming, the inspection carries with it a certain degree of risk because of shock hazard when dealing with high voltage within the close confines of an aircraft.
In addition to the aforementioned difficulties, the cost in terms of money spent for replacement controller units is excessive. Each controller unit costs in excess of several hundred dollars and it is not uncommon to burn out two or three units before finding the short circuit.
The instant invention is the simple, quick and safe way to isolate a defective part, thereby generating savings in both time and money.